A conventional hydraulic power-assisted steering system includes a steering gear having a hydraulic motor. A fluid pump draws hydraulic fluid from a fluid reservoir and supplies the hydraulic fluid to the steering gear. Typically, the engine of the vehicle powers the pump to supply hydraulic fluid from a fluid reservoir to the steering gear. The steering gear includes a control valve. The control valve is responsive to steering inputs for directing hydraulic fluid to the hydraulic motor. The hydraulic motor is operatively connected to the steerable wheels of the vehicle and, when actuated, helps to turn the steerable wheels.
In the conventional hydraulic power-assisted steering system, hydraulic fluid is continually circulating between the pump, the control valve, and the fluid reservoir. As the speed of the vehicle increases, the need for power-assisted steering decreases. The conventional hydraulic power-assisted steering system operates independently of the vehicle speed.